North America Distribution

Facts About

Oakes' evening-primrose is native to northeastern North America, and has been introduced in other temperate regions. It can be found in all New England states, although it is most common on the coastal plain. Near the coast it inhabits dunes, upper beaches and open areas, and elsewhere it is most likely to be found in fields, roadsides and railroads.

the petals are thin and delicate, and pigmented (colored other than green or brown)

Petal base

the petal narrows abruptly at the base

Petal folds or pleats

the petals of the flower do not have folds or plaits

Petal glandular dots or scales

no

Petal hairs (Viola)

NA

Petal hairs on inner/upper surface

there are no hairs on the inner/upper petal surface

Petal length

10–20 mm

Petal length relative to sepals

the petals are about equal in length to the sepals

the petals are longer than the sepals

Petal nectaries

the petals do not have nectaries

Petal number

4

Petal shape

the petal outline is obovate (roughly egg-shaped, but with the widest point above the middle of the leaf blade)

Petal tip shape

the petal tip is retuse (with a blunt or rounded apex and a notch at the center)

Petal tips (Cuscuta)

NA

Raceme attachment (Veronica)

NA

Reproductive system

all the flowers have both carpels and stamens (synoecious)

Scales inside corolla

NA

Sepal and petal color

the sepals are different from the petals

Sepal appearance

the sepals are green or brown, and leaf-like in texture

Sepal appendages

the sepals have one or more appendages on them

Sepal appendages (Oenothera)

the appendages are attached part way down the sepals and separate in bud

Sepal auricles

there is one auricle per sepal

Sepal cilia

the sepals do not have cilia

Sepal color

green to brown

yellow

Sepal length

9–17 mm

Sepal number

4

Sepal orientation

the sepals are curved outwards and downwards from the corolla

Sepal relative length

the sepal lobes are approximately the same length as the fused portion

the sepal lobes are shorter than the fused portion

Sepal shape

the sepal outline is lanceolate (lance-shaped; narrow, gradually tapering from the base to the tip)

the sepal outline is linear (extremely narrow, thread-like)

Sepal tip shape

the sepal tip is acute (is sharply pointed)

Sepal uniformity

all the sepals are about the same size

Sepals fused only to sepals

the sepals are fused to each other (not other flower parts), at least near their bases

the sepals are separate from one another

Spur length

0 mm

Spur number

NA

Stamen appendages

stamen appendages are absent

Stamen attachment

the stamens are attached at or near the bases of the petals or tepals

the stamens are attached at or near the bases of the petals or tepals

Stamen lengths differ

the stamens are all approximately the same length

Stamen morphology

the stamens within each cycle are the same

Stamen number

8

Stamen position relative to petals

NA

Stamen relative length

anything

Stamens fused

the stamens are not attached to one another

Staminodes

there are no staminodes on the flower

Stigma length

2.5–6 mm

Stigma position

the stigmas are positioned at the tip of the style

Style length

0–25 mm

Style petal-like

the styles are not petal-like

Style relative length

the stigma does not protrude beyond the mouth of the corolla

the stigma protrudes beyond the mouth of the corolla

Surface of ovary

the ovary surface has no points, bumps or wrinkles

Umbel flower reproductive parts

NA

Upper lip of bilabiate corolla

NA

Fruits or seeds

Achene relative orientation

NA

Achene shape

NA

Achene surface (Polygonum)

NA

Achene type

NA

Berry color

NA

Capsule color (Viola)

NA

Capsule ribs

the capsule has four prominent ribs or wings

Capsule splitting

the capsule splits by four main valves, teeth or pores

Fruit (pyxis) dehiscence

NA

Fruit beak length

0 mm

Fruit cross-section

the fruit is roughly quadrangular in cross-secgtion

the fruit is round in cross-section

Fruit features (Brassicaceae)

NA

Fruit length

15–40 mm

Fruit length relative to sepals

NA

Fruit locules

four

Fruit shape

the fruit is lanceoloid (narrow, widest below the middle and tapering at both ends)

Fruit stalk orientation

NA

Fruit type (general)

the fruit is dry and splits open when ripe

Fruit type (specific)

the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)

Hair type on fruit

the hairs on the fruits are simple (not branched), don’t have glands, and are not woolly

Hairs on fruit

the fruits have hairs on them

Legumes (Fabaceae)

NA

Mericarp length

0 mm

Mericarp segment shape (Desmodium)

NA

Other markings on berry

NA

Ovary stipe

the ovary or fruit does not have a stipe

Ovary stipe length

0 mm

Placenta arrangement

the plant has axile placentation, in which the ovules are attached where the septa of a compound ovary are united, usually on the central axis, or to the septa themselves

the plant has parietal placentation, where ovules develop on the wall or slight outgrowths of the wall forming broken partitions within a compound ovary

Relative fruit length

0

Rows of seeds in fruit (Brassicaceae)

NA

Schizocarpic fruit compression

NA

Schizocarpic fruit segments

0

Seed length

1.1–1.2 mm

Seed relative length

the seed is longer than it is wide

Seed surface

the seed has pits or depressions on it

Seeds comose

no hairs

Septum in fruit (Brassicaceae)

NA

Wings on fruit

the fruit does not have wings on it

prickles on fruits

the fruits do not have thorn-like defensive structures

Glands or sap

Glands on leaf blade

the leaf blades do not have glandular dots or scales

Sap

the sap is clear and watery

Sap color

the sap is clear

Growth form

Growth form

the plant is an herb (it has self-supporting stems)

Horizontal rooting stem

the plant does not have stolons

Lifespan

the plant lives for two years

Parasitism

the plant is not parasitic

Plant color

the leaves or young stems of the plant are green

Plants darken when dry

no

Spines on plant

the plant has no spines

Underground organs

there is a thickened taproot on the plant

Leaves

Bracteole number (Apiaceae)

0

Bracteoles

the plant has bracteoles between the primary bracts and the flowers

Bracts in plantain (Plantago)

NA

Final leaf segment length (compound lvs only)

0 mm

Final leaf segment length to width ratio (compound lvs only)

0

Final leaf segment width (compound lvs only)

0 mm

Floral bracts

the flower has one or more bracts associated with it

Hairs on underside of leaf

the underside of the leaf is fuzzy or hairy

Hairs on upper side of leaf

the upper side of the leaf is fuzzy or hairy

Hooked hairs on underside of leaf

no

Inflated hairs on leaf

the leaf blade does not have inflated hairs on it

Leaf arrangement

alternate: there is one leaf per node along the stem

Leaf blade base

the leaf has a distinct leaf stalk (petiole)

the leaf has no stalk

Leaf blade base shape

the base of the leaf blade is cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow

Leaf blade base symmetry

the leaf blade base is symmetrical

Leaf blade bloom

the underside of the leaf has no noticeable bloom

Leaf blade edges

the edge of the leaf blade has teeth

the edge of the leaf blade is entire (has no teeth or lobes)

Leaf blade flatness

the leaf is flat (planar) at the edges

Leaf blade hairs

the leaf blade has simple hairs with no glands, and not tangled or wooly

Leaf blade length

35–300 mm

Leaf blade primary vein pattern

the secondary veins branch off at intervals from the primary vein

Leaf blade shape

the leaf blade is elliptic (widest near the middle and tapering at both ends)

the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)

Leaf blade surface colors

the upper side of the leaf blade is relatively uniform in color

Leaf blade texture

the leaf blade has a fleshy or spongy texture

Leaf blade vein pattern

the major veins of the leaf blade branch, but do not rejoin

Leaf blade veins

the leaf blade has one main vein running from the base towards the tip (it may or may not have secondary veins)

Leaf blade width

5–30 mm

Leaf duration

the leaves drop off in winter (or they whither but persist on the plant)

Leaf form

the leaves are green, with an expanded blade and a leaf-like texture

Leaf hair orientation

the hairs are flat against the leaf surface, mostly pointing towards the leaf tip

Leaf sheath length

0 mm

Leaf shiny

the upper side of the leaf is dull or slightly shiny

Leaf spines

there are no spines on the leaf edges

Leaf stalk

the leaves have leaf stalks

the leaves have no leaf stalks, but attach directly to the stem

Leaf stalk attachment to leaf

NA

the petiole attaches at the basal margin of the leaf blade

Leaf stalk base

NA

the petiole base is narrow where it attaches to the stem

Leaf stalk length

At least 0 mm

Leaf teeth and lobes

the edge of the leaf blade is entire (has no teeth or lobes)

the leaf blade margin has outward-pointing teeth

Leaf tip

the tip of the leaf blade is acute (sharply pointed)

Leaf type

the leaves are simple (lobed or unlobed but not separated into leaflets)

Leaf types

There is an abrupt change in appearance of the leaves from the base (or near the base) of the plant to those from further up on the stem, with the basal leaves of conspicuously different shape or form than those slightly higher up.

Leaf variation

the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem

Leaflet number

0

Leaflet petiolules

NA

Leaves per node

there is one leaf per node along the stem

Pinnately compound leaf type

NA

Specific leaf type

the leaves are simple (lobed or unlobed but not separated into leaflets)

Stipels

NA

Stipule edges

NA

Stipule features

NA

Stipule fused to leaf stalk

NA

Stipule length

0 mm

Stipule shape

NA

Stipules

there are no stipules on the plant

Place

Habitat

terrestrial

New England state

Connecticut

Maine

Massachusetts

New Hampshire

Rhode Island

Vermont

Specific habitat

dunes

man-made or disturbed habitats

meadows or fields

sea beaches

Scent

Plant odor

the plant does not have much of a smell

Stem, shoot, branch

Branched tendrils

NA

Direction of stem hairs

the hairs are pressed flat against the plant, pointing towards the plant's tip

the hairs point mostly upwards to outwards

Flowering stem cross-section

the flowering stem is circular, or with lots of small angles so that it is roughly circular

Hair between stem nodes

the stem has hairs between the nodes

Hairs between stem nodes

the hairs on the stem are plain, without glands or branches, and not tangled

Hooked hairs on stem between nodes

no

Leaves on stem

there is at least one full leaf above the base of the flowering stem

Plant height

10–60 cm

Stem bloom

there is no powdery or waxy film on the stem

Stem hair distribution

the hairs on the stem are distributed more of less uniformly

Stem nodes swollen

the stem is not swollen at the nodes

Stem orientation

the stems are upright or angled outwards

the stems trail at the base, but may turn upwards at the tips

Stem roughness between nodes

the stem does not feel rough

Stem spacing

the plant is solitary, or a few plants are growing together

Stem succulence

the stems are not succulent

Tendril origin

NA

Tendrils

the plant does not have tendrils

Wings on stem

the stem does not have wings on it

Wetland Status

Not classified

New England Distribution and Conservation Status

Distribution

Connecticut

present

Maine

present

Massachusetts

present

New Hampshire

present

Rhode Island

present

Vermont

present

Conservation Status

Exact status definitions can vary from state to
state. For details, please check with your state.